Amazon media officials did not immediately return calls from The Associated Press for comment Friday.

Texas officials didn't say how much they think Amazon may owe, but Comptroller Susan Combs said in December that the state lost $541 million in sales taxes on Internet and mail-order sales during 2006.

The question of Texas taxes arose after Amazon sued the state of New York last month, saying it shouldn't have to pay sales taxes because it doesn't have a presence there.

The conflicts with Amazon are part of a larger debate over taxing Internet sales.

Some retailers, such as Plano-based J.C. Penney Co., have complained that competitors who don't collect sales taxes have an unfair advantage.

Legislation now pending in Congress would standardize the taxation of Internet sales while exempting small online retailers.

On its Web site, Amazon says purchases shipped to Kansas, Kentucky, North Dakota or Washington are subject to sales tax. It has operations in all four states.

According to its Web site, it doesn't charge sales taxes in several other states where it also has operations, however.